I have to admit to having not played a Shuker (yet).
Jon de-fretted and ramped my Conklin GT7 and he did a great job of that. Unfortunately, we had a family bereavement and so had to quickly collect the bass and continue our way back up north.
I'm not sure if I like the original designs or not, but his J-basses look very, very good. If I was in the market for a super-J and couldn't stretch to a Sei, then I'd definately look at Shuker as well as Sadowsky Metro and used Lull's and NYC Sadowskys.
His prices must be very keen indeed as they're mentioned quite a bit in this thread. It seems as if he has the balance between quality, affordability and affability, which is a winning combination. As [b]OldGit[/b] says Jon Shuker's order books are full and that tells the story.